JPH0529498A - Cooling system - Google Patents

Abstract

PURPOSE:To provide a cooling system which is used for cooling a plurality of heat generating bodies arranged on a substrate and can efficiently cool the heat radiated from the heat generating bodies. CONSTITUTION:This cooling system 21 contains a heat transfer fluid 37 having excellent thermal conductivity and, at the same time, is constituted of a plurality of cylindrical bodies 25 which cool semiconductor devices 7 while the bodies 25 are brought into contact with and rotated on semiconductor devices 7 and a carrying means composed of a drive motor 29 which successively carries the bodies 25 to the devices 7, roller 33, and guide roller 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for cooling a heating element such as a semiconductor device arranged in a package or on a substrate.

[0002]

2. Description of the Related Art Since a heating element of a semiconductor device such as a VLSI arranged on a substrate generates heat during operation, it is cooled by a cooling device in order to maintain its performance.
Conventional cooling methods include a forced air cooling method in which a plurality of semiconductor devices are simultaneously cooled by blowing air with a fan or the like, and a contact heat conduction method in which a cooling body is brought into contact with a semiconductor device to remove heat from the semiconductor device and cool the semiconductor device. In general, there are natural air cooling method, liquid cooling method and the like other than these cooling methods, but the cooling efficiency is poor as compared with the cooling by the forced air cooling method or the contact heat conduction method.

12 and 13 show cooling devices 1 and 3 based on the above-described conventional forced air cooling method. Figure 1
In the cooling device 1 shown in FIG. 2, a plurality of fans 9 are arranged above the plurality of semiconductor devices 7 mounted on the substrate 5,
Air is blown toward the semiconductor device 7 to cool it.

The cooling device 3 shown in FIG.
The semiconductor device 7 is cooled by forcibly cooling the fins 13 for heat dissipation of the plurality of semiconductor devices 7 housed in the housing 1 by a fan arranged on the side of the housing 11.

However, in the cooling device 1, in order to uniformly blow air to the semiconductor devices 7 in order to enhance the cooling effect of the plurality of semiconductor devices 7, the number of fans 9 is increased or the capacity of the fans 9 is increased. There must be.
Therefore, the cooling device 1 becomes large.

Further, in the cooling device 3, it is necessary to increase the surface area of the fins 13 connected to the semiconductor devices 7 in order to enhance the cooling effect of the plurality of semiconductor devices 7. Therefore, the cooling device 3 becomes large. Furthermore, in this cooling device 3, as shown in FIG.
The wind from the fan is supplied from one direction and the fan 1
The fins 11 located closer to 5 have a higher cooling effect, but as the distance from the fan 15 increases, the air is blocked by the fins 11 located closer to the fan 15, and the cooling efficiency decreases.

Further, FIG. 15 shows a cooling device 17 by a contact heat conduction method. In this cooling device 17, a cooling body 20 is brought into contact with an upper portion of a package 18 to which the semiconductor device 7 is thermally connected, and the heat of the semiconductor device 7 is radiated to the cooling body 20 via the package 18. The semiconductor device 7 is cooled.

However, in the cooling device 17 using the contact heat conduction method, the heat transfer coefficient of the contact surface is very poor. That is, as shown in FIG. 16, solid-to-solid contact should be theoretically regarded as a set of point contacts due to the limit of surface accuracy, and most of the area is through air having a poor heat transfer coefficient.

Therefore, if the contact pressure of the contact surface is increased, the heat transfer coefficient is improved to some extent, but it is obvious that in a semiconductor device or the like, it is not preferable to apply an unreasonable external force to the package 18 as a cause of failure. . Therefore, the performance of the semiconductor device cannot be maintained.

[0010]

As described above, in the cooling devices 1 and 3 according to the above-described conventional forced air cooling method, the scale of the entire cooling device becomes large, and the semiconductor devices are mounted on the substrate 5 at a high density. There is a problem that you can not do. Further, the cooling devices 1 and 3 based on the conventional forced air cooling method have a problem that the cooling efficiency is poor.

Further, in the cooling device 17 based on the contact heat conduction method, since air having a poor heat transfer coefficient is interposed at the contact surface between the package 18 and the package 20, the heat transfer efficiency is poor,
There is a problem of poor cooling efficiency.

Therefore, an object of the present invention is to provide a cooling device capable of efficiently cooling the heat emitted from the heating element.

[0013]

In order to achieve the above object, according to the invention as set forth in claim 1, a plurality of fluid containing a fluid having good heat conductivity and rotating in contact with the surface of the heating element to cool the heating element. It is characterized in that it comprises a cylindrical body and a conveying means for sequentially conveying these cylindrical bodies toward the heating element.

According to the second aspect of the present invention, a high pressure fluid is supplied to the heating element, and a high pressure fluid supplied to the heating element is provided in the tube body. And a nozzle connected to the hole.

According to the third aspect of the present invention, the heat transfer fluid applied between the outer surface of the package and the radiator and the oxide film applied between the heat transfer fluid and the outer surface of the radiator or the package. It is characterized in that layers are provided.

[0016]

According to the first aspect of the present invention, the plurality of cylindrical bodies are sequentially conveyed to the heating element by the conveying means. At this time, the surface of the cylindrical body is coated with a fluid having good thermal conductivity, and by rotating in contact with the surface of the heating element, the heat of the heating element is taken away,
Cool the heating element. Since this cylindrical body contains a fluid having good thermal conductivity on the contact surface with the heating element, it can contact the surface of the heating element without any gap.

Therefore, according to the present invention, since air having poor heat transfer efficiency does not exist between the cylindrical body and the heating element as in the conventional case, the heat of the heating element can be efficiently transferred to the cylindrical element, and the efficiency can be improved. The heating element can be cooled well.

According to the second aspect of the invention, the high-pressure fluid supplied to the pipe is discharged from the hole or nozzle toward the heating element. The high-pressure fluid discharged from the holes or nozzles becomes a low temperature due to the Joule-Thomson effect, and the high-pressure fluid having a low temperature removes heat from the heating element,
Cool the heating element.

According to the present invention, since the fluid having a low temperature is discharged to each of the heating elements provided with the holes or nozzles in the vicinity of the heating element, the heating element can be cooled efficiently. Further, according to the present invention, the heating element can be cooled only by disposing the tube body in the vicinity of the heating element, providing the tube section with a hole or a nozzle, and supplying a high pressure fluid to the tube body. Therefore, it is possible to mount the semiconductor device at high density without increasing the size of the device.

According to the third aspect of the present invention, the heat transfer fluid provided between the outer surface of the package and the radiator and the heat transfer fluid is applied between the heat transfer fluid and the outer surface of the radiator or the package. The oxide film layer makes contact and connects the package and the radiator. In this connection, the oxide film layer and the heat transfer fluid are in contact with each other without a gap, unlike the conventional case where solids are in contact with each other, and the heat of the package is efficiently transferred to the radiator. You can As a result, the heat of the package can be efficiently released to the radiator and the package can be cooled efficiently.

[0021]

Embodiments Next, embodiments of the cooling device according to the present invention will be described with reference to FIGS. It should be noted that the same components as those of the related art are denoted by the same reference numerals in the drawings, and redundant description will be omitted.

First Embodiment FIG. 1 shows a cooling device 21 of the first embodiment. In the figure, the cooling device 21 includes an endless spring member 23 formed in a loop shape, a plurality of cylindrical bodies 25 attached to the spring member 23 in parallel and rotatably, and a spring member 23. The guide roller 27 wound around the roller 33 and the roller 33 fixed to the rotation shaft 31 of the drive motor 29, and the tubular body 25 disposed on the guide roller 27 side and the roller 33 side.
And a cooling unit 35 for cooling the
A heat transfer fluid 37 having good heat conductivity such as silicone oil or grease is applied to the surface of the cylindrical body 25.

The cooling unit 35 may cool the cylindrical body 25 by sending cold air into the housing to remove heat from the cylindrical body 25, and various cooling means can be used.

In order to cool the semiconductor device 7 with the cooling device 21, a plurality of semiconductor devices 7 are arranged outside the linear portion 26 of the spring member 23, and the rotation driving force of the drive motor 29 causes the timepiece of FIG. The elastic member 23 is conveyed in the direction to move the cylindrical body 25 while contacting the surface of the semiconductor device 7. At this time, the semiconductor device 7 is arranged in the linear portion 26 so that the semiconductor device 7 is pressed by the spring member 23.

When the surface of the semiconductor device 7 is enlarged, FIG.
As shown in FIG. 5, the cylindrical body 25 rotates while passing over the surface of the semiconductor device 7 having the uneven shape. During this passage, the heat transfer fluid 37 takes heat of the semiconductor device 7,
It is discharged into the cylindrical body 25 and the semiconductor device 7 is cooled.

As a result, the heat generated from the semiconductor device 7 can be efficiently cooled.

Second Embodiment Next, a second embodiment will be described with reference to FIG. This embodiment is an example in which the semiconductor device 7 is arranged at a different position in the cooling device 21. As shown in FIG. 3, in this embodiment, a plurality of semiconductor devices 7 are arranged on the outside and inside of the linear portion 26 of the spring member 23, and the semiconductor device 7 on the inside is sequentially passed through the cylindrical body 25 to cool. After that, the cylindrical body 25 is sequentially passed through the outer semiconductor device to cool it.

According to this embodiment, many semiconductor devices 7 can be cooled at once.

Third Embodiment Next, a third embodiment will be described with reference to FIGS. 4 and 5. The cooling device 41 of the present embodiment is provided with a high-pressure fluid and is provided with a thin tube 43 provided near the plurality of semiconductor devices 7 in the housing 11, and a thin tube 43 provided in the thin tube 43.
Is composed of pores 45 that eject the high-pressure fluid supplied to the semiconductor device 7 to the semiconductor device 7, a compressor 47 that supplies the high-pressure fluid to the thin tube 43, and a valve 49 that is arranged between the thin tube 43 and the compressor 47. 5, as shown in FIG.
Are located on the surface of the semiconductor device 7.

To cool the plurality of semiconductor devices 7 on the substrate 5 by the cooling device 41, the valve 49 is opened and the high pressure fluid compressed by the compressor 47 is supplied to the thin tube 43. When the high-pressure fluid is supplied to the thin tube 43,
This high-pressure fluid is ejected from the pores 45 toward the surface of the semiconductor device 7. The fluid ejected at this time has a low temperature due to the Joule-Thomson effect, and is ejected to the semiconductor device 7 in this low temperature state. The fluid ejected to the semiconductor device 7 removes heat from the semiconductor device 7 and cools the semiconductor device 7.

According to the present embodiment, the fins for heat dissipation are not required and the apparatus can be downsized so that high density mounting is possible and the fluid whose temperature is lowered by the Joule-Thomson effect can be removed from the semiconductor device 7. Since it sprays on each of them, a higher cooling effect can be obtained.

Fourth Embodiment Next, a fourth embodiment will be described with reference to FIG. As shown in FIG. 6, the cooling device 50 of this embodiment has the same basic configuration as the cooling device of the third embodiment shown in FIG. 4, but an electromagnetic opening / closing valve 51 is provided between each thin tube 43 and the compressor 47. Is provided.

These electromagnetic on-off valves 51 are connected to the control device 53. A temperature detector 55 that is arranged between the semiconductor devices 7 in the housing 11 and detects the temperature between the semiconductor devices 7 is connected to the control device 53.

In order to cool the semiconductor device 7 in the housing 11 with the cooling device, the semiconductor device 7 having a relatively high temperature or the semiconductor device 7 having a high operation frequency is detected based on the detection result of the temperature detector 55. On the other hand, the electromagnetic on-off valve 51 corresponding to the thin tube 43 arranged near these semiconductor devices 7 is opened to supply the high-pressure fluid. As a result, the semiconductor device 7 having a relatively high temperature and the semiconductor device 7 having a high operation frequency can be selectively cooled.

Further, similar to the third embodiment, according to this embodiment, the fin for heat radiation is not required, high density mounting is possible, and the fluid whose temperature is lowered by the Joule-Thomson effect is Since each of the semiconductor devices 7 is locally sprayed, a higher cooling effect can be obtained.

Fifth Embodiment Next, a fifth embodiment will be described with reference to FIG. The present embodiment is an example in which a plurality of pores 45 are provided in the thin tube 43 corresponding to the surface of the semiconductor device 7.

According to this embodiment, the amount of fluid sprayed on the semiconductor device 7 is large, so that the semiconductor device 7 can be cooled intensively.

In the third to fifth embodiments, the Joule-Thomson effect can be enhanced by connecting a nozzle to the pore 45 of the thin tube 43.

Sixth Embodiment Next, a sixth embodiment will be described with reference to FIGS. 8 to 10. As shown in FIGS. 8 and 9, the cooling device 57 of this embodiment includes a cooling plate 20 that is in contact with the package 18 in which the semiconductor chips 7 ′ are housed, and a flexible plate that is connected to the cooling plate 20 to form a container. Sex bellows 59 and this bellows 59
And a radiator 61 connected so as to close the upper opening of the radiator.

A heat medium fluid 63 such as Freon is enclosed in a container formed by the bellows 59 and the cooling plate 20. Further, as shown in FIG. 10, on the surface of the cooling plate 20,
An oxide film treatment with good wettability (brand name BB treatment, brass bond treatment) is applied. This oxide film treatment is a treatment generated on a copper substrate or copper plating. It is black and has a velvety surface immediately after the treatment, and has very good wettability to fluids such as water and easily adheres thereto. Since the surface of the oxide film layer 65 is needle-like fine crystals, the surface area becomes very large as shown in FIG. A space between the oxide film layer 65 and the package 18 is filled with oil, such as water or silicone oil, or a heat conductive heat transfer fluid 67 such as grease.

The heat transferred from the semiconductor chip 7 ′ to the package 18 is transferred to the heat transfer fluid 67 as solid-liquid heat transfer, and then the liquid is transferred from the heat transfer fluid 67 to the oxide film layer 65.
Transmitted as solid heat transfer. Further, it is transmitted from the oxide film layer 65 to the cooling plate 20 by conduction in the solid.

According to the present embodiment, in the conventional heat conduction by solid-solid contact, conduction through air is eliminated, and heat is transferred through a fluid having good thermal conductivity, so that the thermal resistance is large. The heat transfer efficiency is improved. Oxide film layer 65
Has a significantly larger surface area, and improves heat transfer with the heat transfer fluid 67.

Therefore, according to this embodiment, the package 1
The heat from 8 can be efficiently cooled.

Seventh Embodiment Next, a seventh embodiment will be described with reference to FIG. In this embodiment, the surface of the package 18 is subjected to an oxide film treatment,
This is an example in which the heat transfer fluid 67 is filled between them.

According to this embodiment, the heat from the semiconductor chip 7'is transferred to the package 18 and is transferred to the oxide film layer 65 by solid-solid heat conduction, and from the oxide film layer 65 to the heat transfer fluid 67. It is transmitted by the heat conduction of liquid. Then, the heat is transferred from the heat transfer fluid 67 to the oxide film layer 65 by liquid-solid heat conduction, and from the oxide film layer 65 to the cooling plate 20.

According to this embodiment, the heat transfer efficiency is further improved.

[0047]

As described above, according to the cooling device of the present invention, the excellent effect that the heat emitted from the heating element can be efficiently cooled can be obtained.

[Brief description of drawings]

FIG. 1 is a side view showing a first embodiment of a cooling device according to the present invention.

FIG. 2 is an enlarged side view showing the relationship between the cylindrical body and the surface of the semiconductor device.

FIG. 3 is a side view showing a cooling device according to a second embodiment.

FIG. 4 is a side view showing a cooling device according to a third embodiment.

FIG. 5 is an enlarged side view showing a relationship among a semiconductor device, a thin tube, and a fine hole.

FIG. 6 is a side view showing a cooling device according to a fourth embodiment.

FIG. 7 is an enlarged side view showing the relationship between a thin tube, pores and a semiconductor device according to a fifth embodiment.

FIG. 8 is a side view showing a cooling device of a fifth embodiment.

FIG. 9 is a cross-sectional view showing a relationship between a semiconductor chip, a package, and a cooling plate by enlarging a part of FIG.

FIG. 10 is an enlarged side view showing the relationship between the cooling plate and the package.

FIG. 11 is an enlarged side view showing the relationship between the cooling plate and the package of the seventh embodiment.

FIG. 12 is a side view showing a conventional forced air cooling type cooling device.

FIG. 13 is a side view showing another example of a conventional forced air cooling type cooling device.

FIG. 14 is an enlarged side view of the position portion of FIG.

FIG. 15 is a side view showing a conventional contact type cooling device.

16 is an enlarged side view showing a relationship between a package and a cooling plate by enlarging a part of FIG.

[Explanation of symbols]

5 substrates 7 Semiconductor devices 11 housing 21, 41, 57 Cooling device 23 Spring member 25 cylinder 37, 67 Heat transfer fluid 43 thin tube 45 pores 47 Compressor 65 Oxide film layer

Claims (3)

[Claims] 1. A cooling device for cooling a plurality of heating elements arranged on a substrate, wherein a fluid having a good thermal conductivity is applied to the surface of the heating element and the surface of the heating element is rotated in contact therewith to generate the heat. A cooling device comprising a plurality of cylinders for cooling the body, and a conveying means for sequentially conveying the cylinders toward the heating element. 2. A cooling device for cooling a plurality of heat generating elements arranged on a substrate, wherein a high-pressure fluid is supplied and a pipe is provided near the plurality of heat generating elements, and the pipe. A cooling device comprising: a hole provided in a body for discharging a high-pressure fluid supplied to the tube toward the heating element. 3. A cooling device for cooling the heating element by releasing the heat of a plurality of heating elements arranged in the package by a radiator thermally connected to the outer surface of the package, An oxide film layer is formed between the outer surface of the package and the radiator, and a heat transfer fluid is retained on the surface of the oxide film layer to release the heat of the heating element to the heat transfer fluid and the oxide film layer. And a cooling device for cooling the heating element.